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more replace rewrites

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-04-24 00:48:02 -07:00
parent 03ba268219
commit 2793c3af2c
1 changed files with 32 additions and 34 deletions

66
src/ast/rewriter/seq_rewriter.cpp
View file

@ -1420,45 +1420,43 @@ br_status seq_rewriter::mk_seq_replace(expr* a, expr* b, expr* c, expr_ref& resu
}
// is b a prefix of m_lhs at position i?
auto compare_at_i = [&](unsigned i) {
for (unsigned j = 0; j < m_rhs.size() && i + j < m_lhs.size(); ++j) {
expr* b0 = m_rhs.get(j);
expr* a0 = m_lhs.get(i + j);
if (m().are_equal(a0, b0))
continue;
if (!m_util.str.is_unit(b0) || !m_util.str.is_unit(a0))
return l_undef;
if (m().are_distinct(a0, b0))
return l_false;
return l_undef;
}
return l_true;
};
unsigned i = 0;
for (; i < m_lhs.size(); ++i) {
lbool is_prefix = l_true;
for (unsigned j = 0; j < m_rhs.size(); ++j) {
if (i + j >= m_lhs.size()) {
expr_ref a1(m_util.str.mk_concat(i, m_lhs.c_ptr(), sort_a), m());
expr_ref a2(m_util.str.mk_concat(m_lhs.size()-i, m_lhs.c_ptr()+i, sort_a), m());
result = m().mk_ite(m().mk_eq(a2, b), m_util.str.mk_concat(a1, c), a);
return BR_REWRITE_FULL;
}
expr* b0 = m_rhs.get(j);
expr* a0 = m_lhs.get(i+j);
if (!m_util.str.is_unit(b0) || !m_util.str.is_unit(a0)) {
is_prefix = l_undef;
break;
}
if (m().are_equal(a0, b0))
continue;
if (m().are_distinct(a0, b0)) {
is_prefix = l_false;
break;
}
is_prefix = l_undef;
break;
}
if (is_prefix == l_undef)
break;
if (is_prefix == l_false)
lbool cmp = compare_at_i(i);
if (cmp == l_false && m_util.str.is_unit(m_lhs.get(i)))
continue;
expr_ref_vector es(m());
//std::cout << i << " " << m_lhs << "\n";
//std::cout << "rhs: " << m_rhs << "\n";
es.append(i, m_lhs.c_ptr());
es.push_back(c);
es.append(m_lhs.size()-i-m_rhs.size(), m_lhs.c_ptr()+i+m_rhs.size());
result = m_util.str.mk_concat(es, sort_a);
return BR_REWRITE_FULL;
if (cmp == l_true && m_lhs.size() < i + m_rhs.size()) {
expr_ref a1(m_util.str.mk_concat(i, m_lhs.c_ptr(), sort_a), m());
expr_ref a2(m_util.str.mk_concat(m_lhs.size()-i, m_lhs.c_ptr()+i, sort_a), m());
result = m().mk_ite(m().mk_eq(a2, b), m_util.str.mk_concat(a1, c), a);
return BR_REWRITE_FULL;
}
if (cmp == l_true) {
expr_ref_vector es(m());
es.append(i, m_lhs.c_ptr());
es.push_back(c);
es.append(m_lhs.size()-i-m_rhs.size(), m_lhs.c_ptr()+i+m_rhs.size());
result = m_util.str.mk_concat(es, sort_a);
return BR_REWRITE_FULL;
}
break;
}
if (i > 0) {
expr_ref a1(m_util.str.mk_concat(i, m_lhs.c_ptr(), sort_a), m());
expr_ref a2(m_util.str.mk_concat(m_lhs.size()-i, m_lhs.c_ptr()+i, sort_a), m());